The present invention relates to an oneway clutch bearing, and more particularly to an oneway clutch bearing used for preventing a reverse rotation of a spinning reel during fishing.
A conventional apparatus for preventing reverse rotation of a spinning reel is generally provided by a click gear installed inside a rotor of the spinning reel.
For example, Korean Utility Model Publication No. 94-7711, which was assigned to Taiwa Seiko Corporation, discloses an apparatus for preventing reverse rotation of a spinning reel comprising an axis integrally formed on a stopper click coupled with a reverse click gear inside a convexed portion of a rotor. A movable member of the stopper click is operated by an actuating arm, and the axis is journalled on the front of a main body of the reel by the movable member.
A movable body is integrally installed at the axis of the main body of the reel. The movable body is operated by a cam portion of the actuating arm having a lever supported inside the main body of the reel The stopper click is provided with a spring, so that the stopper click is meshed with the click gear 3 to prevent the reverse rotation.
According to the construction of the conventional apparatus for preventing reverse rotation of the spinning wheel as described above, if the lever is moved toward the left side by the actuating arm and thus the stopper click is supported in a state of engaging the stopper click with the click gear for preventing reverse rotation, the rotor can be rotated in the clockwise direction but not in the counterclockwise direction due to the engaged state of the stopper click and the click gear. Meanwhile, if the lever is moved toward the right side by the actuating arm so that the stopper click is in a state of disengaging the stopper click from the click gear, the rotor can be freely rotated in either direction.
However, the conventional apparatus for preventing reverse rotation has a problem that the rotor slips upon preventing the reverse rotation. Therefore, it is a general practice to enlarge a gear tooth portion to ensure the engaged state of the stopper click and the click gear. The number of gear teeth reduces in inverse proportion to the size of the gear tooth section, and the reduction of the number of the gear teeth increases the angle of the guidance to reverse rotation. This disables a prompt prevention of the reverse rotation.
Moreover, when a stopper click is positioned on a ridge of the gear, if the lever is moved toward the right side for the purpose of preventing the reverse rotation, the rotor slips off the same length as the gear tooth portion until the end portion of the click reaches a valley of the gear tooth portion. Accordingly, the conventional apparatus for preventing reverse rotation has a drawback of not fully guaranteeing an instantaneous braking.
Meanwhile, Japanese Utility Model Laid-Open No. 64-38963 discloses an apparatus for preventing reverse rotation, in which an oneway clutch bearing is mounted around the internal circumference of a latch wheel, and a number of rollers of the oneway clutch bearing are fitted around the external circumference of a bushing of a rotating axis.
However, the above apparatus has a drawback in that the rolling velocity of the roller contacting surface decreases due to the small diameter of the rotating bushing, into which the rollers are fitted. This creates a problem of not fully guaranteeing an instantaneous braking. Also, a load is partially put on the abutting surface of each component when preventing reverse rotation, thereby resulting in a possible deformation and a low durability of the roller.
The conventional bearing has no on/off switching function, and operates in uni-direction, thereby posing a problem of additionally providing a separate apparatus around the periphery of the oneway clutch bearing. For instance, the apparatus disclosed in Japanese Patent Laid-Open No. 64-38963 has a construction in which a gear is fitted into an outer periphery of the oneway clutch bearing to prevent its rotation, while the gear teeth are detachably engaged with the gear. Thus, the conventional apparatus not only has a complicated construction but also requires a wide mounting space.
In view of the above drawbacks, U.S. Pat. No. 5,494,232 issued to Hirano et al. on Feb. 27, 1996 (xe2x80x9cHiranoxe2x80x9d) discloses another apparatus for preventing reverse rotation of a spinning reel used for fishing. Referring to FIG. 4, the apparatus for preventing reverse rotation disclosed in Hirano comprises a circular holder 109 rotatably mounted on a bushing, a circular external frame 110 rotatably fixed on a reel casting, and rolling members 107 retained by the circular holder 109 and the circular external frame 110. The circular holder 109 comprises a guide recess 108 for receiving the rolling members 107 therein. Each guide recess 108 has an open slot 108xe2x80x2 at its lower portion, and the rolling members 107 received by the guide recess 108 through the open slot 108xe2x80x2 is partially exposed to be contacted with the bushing. The rolling members 107 contact with the internal surface of the circular external frame 110 to function as a wedge. A spring 111 is provided inside the guide recess 108 for biasing the rolling members 107 to wedge the bushing 6.
According to the above construction, the spiral function of the rolling members 107 is generated by the internal circumference. Specifically, if the rolling members 107 are positioned at the concave portion 122 by means of the rectangular internal surfaces 121, 123 of the circular external frame 110, the bushing can freely rotate in clockwise and counterclockwise directions. However, if the rolling members 107 are positioned apart from the concave portion 122, reverse rotation of the bushing is prevented due to a frictional contact with the rolling members 107.
According to the above construction, one of the rolling members 107 is received between the two internal surfaces 121, 123 of the circular external frame 110. Thus, the internal surface of the circular external frame 110 has an octagonal shape. Considering the size of the apparatus as well as the rotation in both directions of the circular holder mounted on the spinning reel, it is practically impossible for the internal surface to have a geometrical shape which is more rectangular than octagonal. Accordingly, the number of rolling members is limited to four. In that case, if any of the rolling members 107 is damaged or the function of the spring for easing the rolling members deteriorates, the bushing is offset to that direction, thereby being unable to prevent reverse rotation of the bushing. Also, the apparatus for preventing reverse rotation as disclosed in the aforementioned patent has a complicated construction with numerous fittings, thereby increasing the manufacturing cost.
Another clutch bearing is disclosed in Korean Utility Model Unexamined Publication No. 96-10656, as shown in FIG. 5. The clutch bearing includes a bearing cover with a clearance adjusting groove formed on an inner surface, and a bearing holder with a roller bearing. The clutch bearing has some problems as below followings:
Firstly, since the bearing holder is made of a metal, it is difficult to precisely machine bearing receiving grooves and bearing guide protrusions of the bearing holder.
Secondarily a spring supporting the roller bearing is separate from the bearing holder. Accordingly, because the bearings are inserted into the bearing holder through the bearing receiving grooves formed on an outer periphery of the bearing holder, the bearing holder has to be maintained in a horizontal State to receive the bearings. Also, while all of bearings are completely inserted into the bearing holder, the bearing holder can be inserted into the bearing cover. This assembling operation is very cumbersome, and a time needed to assembly it is extended.
Finally, since the spring is separately inserted into the bearing holder, the spring has to have a shape of K so that the spring can smoothly operate. Because the spring has a short length due to its shape, the bearing is stiff in an off-mode,
Therefore, an object of the present invention is to resolve the above problems, and to provide an oneway clutch bearing capable of being assembled easily.
Another object of the present invention is to provide an oneway clutch bearing capable of preventing a roller bearing from being contacted with a bushing in an on-mode.
To achieve the above object, there is provided an oneway clutch bearing using a frictional force between roller bearings and a bushing, the clutch bearing comprising: a housing made of plastic resin, and including an outer wall, an inner wall, and a bottom portion engaging the Outer wall and the inner wall, the bottom portion being provided at its center with a circular opening, and a plurality of bearing supporting bars being protruded at a constant interval from an edge of the circular opening, a bearing holder made of plastic rosin, and rotatably disposed between the outer wall and inner wall of the housing; a bearing guide disposed above the bearing holder, inserted between the inner wall and the outer wall of the housing, and having a plurality of arcuate recesses to receive the rollers, and a cover mounted onto an opened end of the housing.
A height of the bearing supporting bar is slightly higher than that of the outer and inner walls, so that the free end of the bearing supporting bar is inserted to the cover. A plurality of through openings arc formed between the outer wall and the inner wall.
The bearing holder includes a circular base, a tap protruded downward from the base, a plurality of retaining bars protruded upward from the base, and an inverse-U shaped resilient member. The circular base of the bearing bolder is inserted into the hollow portion of the housing, with the tap being inserted into a slit of the housing.
According to the present invention, since the length of the spring of the bearing holder is short, the tension of the spring is weak, thereby making the rotation in clockwise direction smooth.
The oneway clutch bearing of the present invention provides an advantage in that since the spring guide can be made by a drawing process, the manufacturing time and cost are shorter than those of a conventional clutch bearing.
Also, since the upper side of the housing is opened, the bearing holder, the bearing guide, and the roller bearing can be inserted into the housing by turns, so that the assembly of the clutch bearing is easy.